Bordetella pertussis organisms produce a number of substances, some of which are biologically active in the host animal and some of which appear to be important in the metabolism of the bacteria. One component of the organism causes an increase in circulating insulin levels in the host animal. Another bacterial product, which causes dermonecrosis and death in mice and rats, was shown to be located intracellularly. The bacterial adenylate cyclase, which has been shown previously to be predominantly extracytoplasmic in this organism, demonstrates change in its activity which are dependent upon phase and conditions of growth and culture media being used. The adenylate cyclase and the factor which increases insulin levels have been shown to be present in some standard Pertussis vaccines. BIBLIOGRAPHIC REFERENCES: Hewlett, E.L., Urban, M.A., Manclark, C.R. and Wolff, J.: Extracytoplasmic adenylate cyclase of Bordetella pertussis. Proc. Natl. Acad. Sci. USA 73: 1926-1930, 1976. Hewlett, E.L., Manclark, C.R. and Wolff, J.: Adenylate cyclase in Bordetella pertussis vaccine. J. Inf. Dis. Supplement, August, 1977.